1. Field of the Invention
The present invention relates to firearms, and more particularly to an improved automatic gas-operated rifle, of the type exemplified by the M16.
2. Brief Description of the Prior Art
The M16 automatic rifle is a standard of the American military. Originally known as the AR-15 of the ArmaLite Division of the Fairchild Engine and Airplane Company, it was designed by Eugene M. Stoner in 1957-1958. It is currently produced by Colt Industries. Modified versions of the M16, respectively the M16A1 and M16A2, are also currently in use by the U.S. armed services. As used herein, the term M16 includes the M16A1 and M16A2 versions. The term "M16-type" rifle or weapon includes all versions of the AR-15 and M16 ever produced, in production as well as in experimental versions and prototypes.
Although the M16 has long been one of the most widely used American military weapons, it is not without shortcomings. The M16 has a low tolerance for moisture. Military tests in 1958 at the Aberdeen Proving Ground and the Infantry Board, in 1959 at the Springfield Armory, and in 1962 again at Aberdeen indicated that the presence of water in the bore of the M16 constitutes a considerable safety hazard, including possible rupture of the barrel. See The Great Rifle Controversy by Edward C. Ezell at 181 (Harrisburg, Pa.: Stackpole Books 1984).
As stated in U.S. Army Field Manual FM 23-9 (1974) "Failure to remove water from the barrel may result in the weapon blowing up. If the weapon has been submerged in water, exposed to heavy rain and/or dew, or if there is any reason to believe there is excess moisture in the barrel, point the muzzle of the weapon toward the ground and pull the charging handle 2 to 3 inches to the rear, breaking the seal formed by the chambered round and allowing the water to drain out of the barrel."
Combat use in the damp climate of Vietnam graphically demonstrated this shortcoming, and pointed up the need for frequent cleaning of the M16 to avoid fouling and jamming. Yet in the heat of battle, one of the first "nonessentials" to be discarded by a combat soldier is his weapon cleaning kit.